Dragan Drop, the illustrious guy

Dragan Drop, do you know him? He´s the guy all the sales persons ask after. 'Can't you just drag and drop the assignment on the resource'. He's a popular guy, that Dragan fellow. We started talking about him in my Apple days, when he made his powerful entry into our lives. I often love him, but sometimes, he's just not the right guy.
My years as a Microsoft Project tutor made me realize that Dragan is like those good looking guys you find attractive on the first date. But then you realize that he's undependable and not very good in the long run. (And with this I mean that Drag-and-drop is a very very good idea in some applications, but it's not a good solution in others.)
In Microsoft Project you can drag and drop tasks, appointments, resources, etc. And that is nice. If you are very stable on your hand. And if you can see the starting point and the finishing point at the same time. And curse the user who can't hold on to the mouse button until he's found the right goal. If I had gotten a dime for every Microsoft Project student who said 'But where did it go, I dropped X somewhere...' I would be a rich mommy. And since the move result in recalculations of the project, a faulty drag-and-drop adventure can be devastating.
So, what all (and I really mean ALL) my users learned was, don't use the Dragan fellow for more than a one-night-stand. Nice and easy. But when things get complicated, aim for the boring fat guy.